Walking mine roof support



April 1, 1969 w. WEIRICH ETAL 3,435,620

WALKING MINE ROOF1 SUPPORT Filed July 11, 1967 Sheet of 3 I INVENTOR WM 8.8 m

ATTORNEY A ril 1, 1969 w. WEIRICH ETAL 3,435,620

WALKING MINE ROOF SUPPORT Filed July 11, 1967 Sheet 3 Of 5 III III

III

nu I H iii J V l E ATTORNEY United States Patent.

3,435,620 WALKING MINE ROOF SUPPORT Walter Weirich, Dortmund, and Giinther Kuschke,

Castrop-Rauxel, Germany, assiguors to Gewerkschaft Eisenhuette Westfalia, Altluuen, Germany Filed July 11, 1967, Ser. No. 652,509 Claims priority, application Germany, July 12, 1966, H 59,924 Int. Cl. E2141 11/00 US. CI. 61-45 7 Claims ABSTRACT OF THE DISCLOSURE A walking mine roof support including elongated substantially horizontally arranged guide and fluid-operated advancing means including telescopically arranged members, a pair of frames substantially parallel to said guide and advancing means and respectively arranged at opposite sides of the latter and each including a pair of expandable and collapsible pit props spaced in direction of said guide and advancing means from each other and connected to each other by packs of leaf springs, with the leaf springs of one frame fixedly connected at an intermediate portion thereof to one of the telescoping members of said guide and advancing means by rigid transverse connecting means and the leaf springs of the other frame fixedly connected at an intermediate portion thereof to another of the telescoping members, and length adjustable connecting means in the form of fluid-operated cylinder and piston means extending between and pivotally connected to one of the props of one frame and to that telescoping member to which said one frame is connected for steering the direction of movement of said walking mine roof support.

Background of the invention The present invention relates to a walking mine roof support in which elongated guide and advancing means are arranged between a pair of frames carrying expandable and collapsible pit props, whereby the guide and advancing means are connected by rigid transverse connecting means to spring elements which connect the pit props of each frame.

Such walking mine roof supports are well known in the art and serve to support the roof of a mine gallery while being able to advance toward the mine face. A walking mine roof support of this type is for instance disclosed in the copending application Serial No. 391,149, now Patent 3,328,968, in which the cylinder portions of the expandable and collapsible mine props of each frame are connected by two packs of lead springs which are superimposed upon each other and which abut against each other at an intermediate portion thereof while being bent away from each other at opposite ends, and in which the opposite ends of the lower pack of leaf springs are hingedly connected to sole plates connected to the bottom ends of the cylinder portion of the props while the opposite ends of the upper pack of leaf springs are connected by stirrups to the cylinder portions of the props so as to be slidable in longitudinal direction of the same. The intermediate abutting portions of the two packs of springs are connected to each other by brackets and the brackets which connect the spring packs of the pair of frames are respectively hingedly connected by rigid transverse members which in turn are connected at the other ends thereof to the inner and outer guide members of the guide and advancing means located between the frames.

Even though such an elastic connection of the pit props of each frame permits and adjustment of the position 3,435,620. Patented Apr. 1, 1969 ice of the props to any inclination of the sole of the mine gallery so as to assure a substantially vertical position of the props with an adjustable pretension, there occur, especially when the sole of the mine gallery is considerably inclined, undesired tendencies of the frames to change their direction during advancement, especially when the sole of the mine gallery is inclined in such a manner that the props, respectively the frames, will be inclined in a direction transverse to the advancing direction.

It is an object of the present invention to overcome this disadvantage of walking mine roof supports known in the art.

his a further object of the present invention to provide for a walking mine roof support in which the direction of advancement of the mine roof support can be controlled and in which undesired deviations from the desired advancing direction resulting from unevenness or inclination of the mine sole can be corrected.

It is an additional object of the present invention to provide for a walking mine roof support of the aforementioned kind which is composed of relatively few and simple parts and in which steering of the advancing direction can be controlled in a simple manner.

Summary of the invention With these objects in view, the walking mine roof support according to the present invent-ion mainly comprises substantially horizontally arranged elongated guide and advancing means having a longitudinal axis and including an outer guide member, an inner guide member slida-bly guided in the outer guide member and hydraulic means for moving the members relative to each other in axial direction of the guide and advancing means, a pair of frames respectively located to opposite sides of the elongated guide and advancing means and each including a pair of expandable and collapsible substantially upright pit props spaced .in direction of the aforementioned axis from each other and each having a lower cylinder portion and an upper piston portion fiuidtightly guided in the cylinder portion, and packs of elongated leaf springs located above the floor and respectively connected at opposite ends to bottom portions and upper portions of the cylinder portions of each pit prop, a pair of rigid connecting means extending transverse to the elongated guide and advancing means and one fixedly connected at one end to the outer member thereof and at the other end to an intermediate portion of the packs of springs of one frame and the other fixedly connected at one end to the inner member of the guide and advancing means and at the other end thereof to an intermediate portion of the packs of springs of the other frame, and length adjustable connecting means preferably in the form of hydraulic cylinder and piston means connected at one end to the cylinder portion of one pit prop of one frame and at the other end to that one member of the guide and advancing means which is connected by one of the transverse connecting means to said one frame.

The hydraulic cylinder and piston means is preferably connected to the lead-ing pit prop of that frame which during advance of the mine roof support will trail the other frame.

By thus connecting the pit prop with the corresponding member of the guide and advancing means by hydraulic cylinder and piston means, the advantage is obtained that the length of this connection may be changed .indepen dent from the forces resulting from the inclination of the sole of the mine gallery and so that it is possible to forcibly adjust the desired distance.

The hydraulic cylinder and piston means which act as tension or pressure members between one pit prop of one frame and the corresponding member of the guide and advancing means while connecting the respective frame to the guide and advancing means, serve mainly to control the direction of advancement of the frames. The hydraulic cylinder and piston means are constructed in such a manner that they can be maintained in any expanded or contracted position so as to control the ad vancing direction of the mine roof support in that the pack of leaf springs, which will be tensioned in transverse direction during extension or contraction of the hydraulic cylinder and piston means and maintenance of the props in expanded condition, will be relaxed when the pit props of the respective frame are collapsed so that the respective frame will be turned in the desired advancing direction.

In other words, the hydraulic cylinder and piston means will produce a change of the angular position of the respective frame with respect to the elongated guide and advancing means by elastic deformation especially of the spring packs of the respective frame. It is to be understood that the members of the guide and advancing means, the spring packs of the frames and the connection of the spring packs to the members of the guide and advancing means are not purposely constructed so that the two frames may include a small angle with respect to the guide means, but the invention is based on the recognition that the relatively stiff and rigid elements which form the mine roof support can be elastically deformed so as to obtain a suificient change of the angle without producing a permanent deformation of any of the members. The present invention is therefore based on the combination of two principles, that is to connect the pit prop of a least one frame with a corresponding member of the guide and advancing means by cylinder and piston means and to form the frames, the guide and advancing means and the connection between the frames and the guide and advancing means as rigid as in mine roof supports which are not provided with cylinder and piston means between one prop and the guide and advancing means. The operation of the walking mine roof support according to the present invention follows from the above-mentioned principles on which the invention is based, that is by expanding or contracting the cylinder and piston means while the pit props are maintained in expanded position tight-1y engaging the roof and the floor of a mine gallery, the angular position of the elongated guide and advancing means relative to the two frames may be changed by elastic deformation of the various elements, especially the spring packs of the two frames, so that at the moment the pit props of one frame will be moved to the collapsed position thereof, this frame will automatically turn to a position in which the frame will again be parallel to the elongated guide and advancing means.

While various constructions are known in the art in which the direction of a walking mine roof support may be changed, the construction according to the present invention differs from known arrangements by the simplicity of its construction and operation. The forces necessary for alternatingly advancing the two frames are transmitted from the respective members of the guide and advancing means to the frames only by the rigid transverse members which connect the respective members of the advancing means to intermediate portions of the spring packs of the two frames and the hydraulic cylinder and piston means which connect one pit prop of one frame to the respective member of the advancing means serve only to change the direction of advancement of the walking mine roof support. The control of the direction of the advancing movement is also exceedingly simple and can be obtained by properly controlling only a single cylinder and piston means and the desired change of direction may be stored in a latent manner while the pit props are in the engaged or expanded position so that upon release of the pit props of one frame the desired change in direction will be automatically controlled.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

Brief description of the drawing FIG. 1 is a schematic side view of the walking mine roof support according to the present invention;

FIG. 2 is a schematic partly sectioned front view drawn to a slightly enlarged scale;

FIG. 3 is a schematic partly sectioned top view;

FIG. 3a illustrates a detail of FIG. 3 at an enlarged scale;

FIG. 4 is a schematic top view similar to FIG. 3 and showing the springs of the two frames in stressed condition; and

FIGS; 5-7 are diagrammatic views illustrating how change of the advancing direction of the mine roof support may be obtained.

Description of the preferred embodiments Referring now to the drawings, and more specifically to FIGS. l-3 of the same, it will be seen that the walking mine roof support according to the present invention basically comprises substantially horizontally elongated guide and advancing means ,6 and a pair of frames F and F respectively arranged to opposite sides of the elongated guide and advancing means G and normally extending substantially parallel thereto.

The frame F comprises, as best shown in FIG. 1, a pair of substantially upright expandable and collapsible pit props 1 and 2 of known construction having each a lower cylinder portion in which an upper piston portion is slidably guided to project in the expanded position beyond the upper end of the cylinder portion and shields 4 and 5 may be respectively connected to the upper ends of the piston portions of each prop, which shields may be hingedly connected by a connecting piece 6, whereas sole plates 3 are preferably tiltably connected to the lower ends of the cylinder portions of each .prop. The props 1 and 2 which are spaced in direction of advancement of the mine roof support from each other are connected to each other by a pair of spring packs 7 and 8 which are superimposed upon each other and bent relative to each other, as clearly shown in FIG. 1, to abut against each other only at an intermediate portion between the ends of the two spring packs. The opposite ends of the lower spring pack 8 are hingedly connected in a known manner as schematically shown in FIG. 1, to extensions of the sole plates 3, whereas the opposite ends of the upper spring pack 7 are respectively connected to stirrups 9 to the cylinder portion of the respective prop so that the stirrups may slide in longitudinal direction of the prop. Each of the spring packs is formed by a plurality of superimposed leaf springs and the two packs 7 and 8 are connected to each other at the abutting intermediate portions thereof by clamping members 10, only schematically shown in FIG. 1. The frame F likewise includes a pair of expandable and collapsible props 11 and 12 and a pair of superimposed spring packs 13 and 14 respectively connected to the sole plates 3 of the props 11 and 12 and to the cylinder portions thereof in the same manner as shown for the frame F in FIG. 1. In FIG. 3, the top shields which are respectively connected to the props are omitted and the connection of the spring packs to the pit props and the sole plates thereof as well as the clamps which clamp the spring packs of each frame at the abutting portions thereof are only shown in a simplified manner.

The elongated guide and advancing means G which are located between the two frames F and F and which normally extend parallel thereto may comprise an outer guide member 15 of substantially C-shaped configuration so as to present an elongated slot directed toward the frame F and an inner guide member 16 in form of a cylinder slida-bly guided in the outer guide member 15 for movement relative thereto in axial direction. A piston 17 is fluid-tightly guided in the cylinder 16 and a piston rod 18 is connected at one end thereof in any convenient manner to the piston 17 for movement therewith and projects with the other end thereof beyond the cylinder 16. The piston rod 18 is connected at the projecting end in a manner not illustrated in the drawings to the outer guide member 15 so that the latter is constrained to move with the piston rod 18. The front end portion of the piston rod 18 carries a member 19 which may abut or which may be attached to a conveyor extending transverse to the elongation of the piston rod in front of a mine face to be mined. The clamp which clamps the abutting portion of the spring packs 7, 8 of the frame F to each other projects with an inner end thereof between the pair of legs of a U-shaped bracket 20 and is hingedly connected thereto 'by means of a hinge pin 21 extending parallel to the axis of the piston rod 18. The bracket 20, in turn, is fixedly connected in any convenient manner to the outer guide member 15. There is substantially no clearance between the two legs of the bracket 20 and the clamp 10 so that during axial movement of the guide member the frame F connected thereto by the members 10 and is constrained to move in the same direction. The clamp 10 which connects the spring pack 13 and 14 of the frame F is connected in the same manner by a pivot pin 21 to a U-shaped bracket 20', which in turn is fixedly connected in any convenient manner to the inner cylinder member 16 of the elongated guide and advancing means G.

The walking mine roof support so far described is known in the art and described in further details in the copending application 391,149.

The walking mine roof support according to the present invention differs from the aforementioned mine roof support known in the art by the means for changing the direction of advancement of the mine roof support, respectively for correcting an undesired deviation from the desired advancing direction. These means are constituted by length adjustable connecting means preferably in the form of hydraulic cylinder and piston means including a cylinder 30, a piston 31 substantially fluid-tightly guided in the cylinder for movement in axial direction and having a piston rod 32 connected at one end thereof to the piston 31 and projecting with the other end beyond one end of the cylinder 30. The end of the piston rod 32 which projects beyond the one end of the cylinder 30 is connected by means of a hinge pin 33 which extends substantially parallel to the longitudinal axis of the guide and advancing means G to a pair of hinge members 34 which project spaced from each other and which are fixedly connected to the cylinder portion of the prop 11. As shown in FIG. 3, there is ample clearance between the inner faces of the hinge members 34 and the end of the piston rods 32 projecting there between and the bore 32' through the piston rod gradually widens from a central portion toward opposite ends thereof as shown in FIG. 3: so that the axis of the piston rod 32 may include with the axis of the pivot pin 33 an angle different from 90 degrees for the purpose as will be described later on. A central projection 35 projects fixedly connected from the other end of the cylinder 30, by being for instance integrally made with the right bottom of the cylinder as viewed in FIG. 3, and the projection 35 projects with ample clearance between two hinge members 37 fixedly connected to the cylinder member 16 and projecting through the longitudinal slot of the outer guide member 15. The projection 35 is hingedly connected to the hinge members 37 by a pivot pin 36 extending substantially parallel to the pivot pin 33. Pressure fluid, for instance pressure oil, may be fed in a known manner from a source of pressure fluid, not shown in the drawing, in and out of the cylinder 30 to opposite sides of the piston 31 therein, as indicated schematically by the arrows shown in FIG. 3.

Instead of connecting a cylinder and piston means 30-32 to the front or leading prop 11 of the frame F and to the inner cylindrical member 16, it is also possible to provide cylinder and piston means of the aforementioned described manner and to hingedly connect the same in the described manner to the rear prop 2 of the frame F and to the outer guide member 15 to which the frame F is connected, as indicated in dash-dotted lines in FIG. 3.

The above-described mine roof support may be operated as follows:

Normally, the cylinder spaces to opposite sides of the piston 31 therein are relieved of pressure so that the piston 31 may take any position relative to the cylinder 30. If it is now desired to change the advancing direction of the mine roof support or the position of the mine roof support as indicated in the diagrammatic view of FIG. 5 to the position as shown in the diagrammatic view of FIG. 6, pressure fluid is fed to the right side of the piston 31, as viewed in FIG. 4 so that the piston 36 moves to the left end of the cylinder 30, as viewed in FIG. 4, so that the over-all length of the cylinder and piston lrneans 30-32 is expanded whereby the spring packs of the frames F and F will be stressed and bent, as schematically indicated in FIG. 4, and so that the axis of the elongated guide and advancing means G will be inclined with respect to the frames F F The props 1 and 2 of the frame F will then be moved to the collapsed position so that the stress in the spring packs 7, 8 of the frame F will be released, and so that the frame F will take a position parallel to the longitudinal axis of the guide and advancing means G. The frame F is then advanced by the guide and advancing mechanism G in a direction parallel to the axis thereof and subsequently thereto the props 1 and 2 of the frame F are expanded so that the top shields and bottom plates connected to these rops will engage the roof and the sole of the mine gallery. Subsequently thereto, the props 11 and 12 of the frame F will be moved to the collapsed position so that the stress in the spring packs thereof will be released and the frame F will also move to a position parallel to the axis of the elongated guide and advancing means G. Thereafter, the frame F is also advanced and the mine roof support will therefore now advance in the direction as indicated in FIG. 6. Evidently, the advancing direction may be changed and the position of the mine roof support may be turned to the position shown in FIG. 7 by feeding pressure fluid into the cylinder 30 to the other side of the piston 31 so that the over-all length of the cylinder and piston means 30-32 may be reduced as schematically indicated in FIG. 7. It is further evident that the aforementioned cylinder and piston means may not only be used for changing the advancing direction of the walking mine roof support but also to correct any deviation from the desired direction due to inclination of the mine sole.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of walking mine roof supports with means for changing the advancing direction of the mine roof support differing from the types described above.

While the invention has been illustrated and described as embodied in a walking mine roof support with fluid operated cylinder and piston means for changing the advancing direction of the mine roof support, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

We claim:

1. A walking mine roof support, comprising, in combination, substantially horizontally arranged elongated guide and advancing means having a longitudinal axis and including an outer guide member and an inner guide member slidably guided in the outer guide member and hydraulic means for moving said members relative to each other in axial direction of said guide and advancing means; a pair of frames respectively located to opposite sides of said elongated guide and advancing means and each including a pair of expandable and collapsible substantially upright pit props spaced in direction of said longitudinal axis from each other and each having a lower cylinder portion and an upper piston portion fluid-tightly guided in the cylinder portion and leaf spring means extending between the pair of props and respectively connected at opposite ends thereof to bottom portions and upper portions of the cylinder portions of the two props; a pair of transverse connecting means extending transverse to the elongated guide and advancing means and one fixedly connected at one end to said outer member thereof and at the other end to an intermediate portion of said leaf spring means of one frame, and the other of the transverse connecting means being fixedly connected at one end thereof to said inner member of said guide and advancing means and at the other end thereof to an intermediate portion of said leaf spring means of the other frame; and length adjustable connecting means connected at one end thereof to the cylinder portion of one pit prop of one frame and connected at the other end thereof to that one member of said guide and advancing means which is connected by one of said transverse connecting means to said one frame.

2. A walking mine roof support as defined in claim 1, wherein said length adjustable connecting means comprises fluid operated cylinder and piston means.

3. A walking mine roof support as defined in claim 2, wherein said cylinder and piston means is pivotally connected at one end thereof to the cylinder portion of said one pit prop tiltable about a pivot axis substantially parallel to said longitudinal axis and at the other end to said one member of said guide and advancing means likewise tiltable about a pivot axis substantially parallel to said first mentioned pivot axis.

4. A walking mine roof support as defined in claim 2, wherein said cylinder and piston means is connected at said one end to said cylinder portion of the leading pit prop of that frame which during advance of the mine roof support will trail the other frame.

5. A walking mine roof support as defined in claim 2, wherein said cylinder and piston means comprises a cylinder having a projection at one end, a piston slidably guided in said cylinder, and a piston rod connected at one end to said piston and projecting with the other end thereof beyond the other end of said cylinder, and including two pairs of binge members respectively connected to the cylinder portion of said one pit prop and to said one member of said guide and advancing means, said projection and said piston rod respectively extend with ample clearance between the respective pair of hinge members and are respectively pivotally connected thereto for tilting movement about substantially horizontal axes extending parallel to said longitudinal axis.

6. A walking mine roof support as defined in claim 5, wherein the piston rod is connected at the other end thereof to said pair of hinge members for limited universal tilting movement with respect thereto.

7. A walking mine roof support as defined in claim 5, wherein said other end of said piston rod is connected to the respective pair of hinge members by a pivot pin extending through aligned bores of the piston rod and the hinge members, and in which the bore in the piston rod increases from a center portion of the bore to opposite ends thereof.

References Cited UNITED STATES PATENTS 3,225,547 12/1965 Hoffmann 61-45 3,362,169 l/l968 Groetschel 61-45 3,367,117 2/1968 Weirich et al. 61-45 JACOB SHAPIRO, Primary Examiner. 

